Expiry of Time Alignment Timer in Primary Timing Advance Group

Abstract

A wireless device can receive configuration parameters indicating a first timing advance group (TAG) for a cell and a second TAG for the cell. The first TAG may be a primary TAG (PTAG). A first time alignment timer (TAT) associated with the first TAG can expire. In response to the expiry of the first TAT, the wireless device may set the second TAG as the PTAG. The wireless device may further transmit uplink signals via the cell.

What is claimed is: 
     
         1 . A method comprising:
 receiving, by a wireless device, configuration parameters indicating:
 a first timing advance group (TAG) for a cell, wherein the first TAG is a primary TAG (PTAG); and 
 a second TAG for the cell; 
   in response to a first time alignment timer (TAT) associated with the first TAG expiring, setting the second TAG as the PTAG; and   transmitting uplink signals via the cell.   
     
     
         2 . The method of  claim 1 , wherein the setting is further in response to a second TAT running. 
     
     
         3 . The method of  claim 2 , wherein the second TAT is associated with the second TAG. 
     
     
         4 . The method of  claim 2 , wherein the configuration parameters indicate the first TAT and the second TAT. 
     
     
         5 . The method of  claim 1 , wherein the configuration parameters are radio resource control (RRC) configuration parameters. 
     
     
         6 . The method of  claim 1 , further comprising receiving one or more messages comprising the configuration parameters. 
     
     
         7 . The method of  claim 1 , wherein
 a first transmission configuration indication (TCI) state is associated with the first TAG; and   a second TCI state is associated with the second TAG.   
     
     
         8 . An apparatus comprising:
 one or more processors; and
 memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform: 
 receiving, by a wireless device, configuration parameters indicating:
 a first timing advance group (TAG) for a cell, wherein the first TAG is a primary TAG (PTAG); and 
 a second TAG for the cell; 
 
 in response to a first time alignment timer (TAT) associated with the first TAG expiring, setting the second TAG as the PTAG; and 
 transmitting uplink signals via the cell. 
   
     
     
         9 . The apparatus of  claim 8 , wherein the setting is further in response to a second TAT running. 
     
     
         10 . The apparatus of  claim 9 , wherein the second TAT is associated with the second TAG. 
     
     
         11 . The apparatus of  claim 9 , wherein the configuration parameters indicate the first TAT and the second TAT. 
     
     
         12 . The apparatus of  claim 8 , wherein the configuration parameters are radio resource control (RRC) configuration parameters. 
     
     
         13 . The apparatus of  claim 8 , further comprising receiving one or more messages comprising the configuration parameters. 
     
     
         14 . The apparatus of  claim 8 , wherein
 a first transmission configuration indication (TCI) state is associated with the first TAG; and   a second TCI state is associated with the second TAG.   
     
     
         15 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of an apparatus, cause the apparatus to perform:
 receiving, by a wireless device, configuration parameters indicating:
 a first timing advance group (TAG) for a cell, wherein the first TAG is a primary TAG (PTAG); and 
 a second TAG for the cell; 
   in response to a first time alignment timer (TAT) associated with the first TAG expiring, setting the second TAG as the PTAG; and   transmitting uplink signals via the cell.   
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , wherein the setting is further in response to a second TAT running. 
     
     
         17 . The non-transitory computer-readable medium of  claim 16 , wherein the second TAT is associated with the second TAG. 
     
     
         18 . The non-transitory computer-readable medium of  claim 16 , wherein the configuration parameters indicate the first TAT and the second TAT. 
     
     
         19 . The non-transitory computer-readable medium of  claim 15 , wherein the configuration parameters are radio resource control (RRC) configuration parameters. 
     
     
         20 . The non-transitory computer-readable medium of  claim 15 , further comprising receiving one or more messages comprising the configuration parameters.